Answer the following
(i) Name the major site where RBCs are formed.
(ii) Which part of heart is responsible for initiating and maintaining its rhythmic activity?
(iii) What is specific in the heart of crocodiles among reptilians?
(i) Bone marrow
(ii) Sino-atrial node (SA node)
(iii) Reptiles have three-chambered heart except crocodile, which has four-chambered heart.